Krystal debuts from Star Fox Adventures. At the beginning of the game, she wields a staff to assist her telepathic abilities. She eventually loses the staff before being imprisoned by Andross. Fox eventually finds the staff and uses it throughout the game.

Krystal's appearance as an Assist Trophy is based off of her appearance in Star Fox Adventures, and her ability to use the staff is based on the opening portion of said game. Ice Blast is the third upgrade for the staff which allows Fox to freeze enemies and environment objects solid for combat and puzzle solving.

Krystal was considered as a potential playable character during development, but was passed over in favor of Wolf, both because of time constraints and because Wolf's movement and animations would be more similar to Fox's and would require less development.[1]

A member of the Star Fox team welcomed in Star Fox Adventures after the team met her on planet Sauria when responding to a distress signal. Krystal is capable of telepathy and is a valuable member in combat. After becoming romantically involved with Fox, their relationship gets very rocky in Star Fox Command.

As befitting her name, Krystal was once imprisoned in a giant crystal. After rescuing her, Fox welcomed her into the team, where her telepathic abilities proved invaluable. She and Fox also became romantically involved. Did her telepathic powers help or hinder that relationship?

As befitting her name, Krystal was once imprisoned in a giant crystal. After rescuing her, Fox welcomed her into the team, where her telepathic abilities proved invaluable. She and Fox also became romantically involved. We can't help but wonder if extrasensory perception helps or hinders a relationship!

Krystal is confirmed to appear in Ultimate as an Assist Trophy. She attacks fighters with her staff and can deal freezing damage. She also once again reprises her role in the Star Fox Smash Taunt on the returning Lylat Cruise stage.